1. Field of the Invention
The present invention relates to an absorption refrigeration machine, and more particularly to a control device for an absorption refrigeration machine.
2. Description of the Prior Art
For example, Japanese Patent Laid-Open No. 62-84267 publication discloses an absorption refrigeration machine provided with a control device which detects a liquid surface of a high temperature generator and which controls a discharge amount of an absorption liquid pump provided in a solution flowpassage from an absorber to a generator.
In the above-described conventional technique, the following properties of the control of the absorption liquid pump is poor at the time of an abrupt variation of load, variation of cooling water temperature, and start and stop of the absorption refrigeration machine. For example, the absorption liquid pump possibly stops at a high liquid surface of the high temperature generator, and the absorption refrigeration machine possibly abnormally stops at a low liquid surface.
Further, Japanese Patent Laid-Open No. 58-160778 publication discloses a control device for an absorption refrigeration machine which detects a cooling water outlet temperature to control a heating amount to a generator, detects an absorption liquid level within the generator to control an amount of a dilute absorption liquid which flows from an absorber to the generator, detects a cooling water inlet temperature to obtain an optimum value of either of a heating amount of the generator with respect to the inlet temperature or an amount of a dilute absorption liquid flowing to the generator, and controls either of the heating amount or the amount of the dilute absorption liquid according to an optimum value.
In the above-described conventional technique, proportional control which detects a level of absorption liquid within the generator to control an amount of dilute absorption liquid flowing from the absorber to the generator, or PID control has been generally carried out.
However, the aforementioned control has a problem in that the responsiveness to the start and stop, gentle load variation, abrupt load variation or variation in temperature of cooling water is poor.